romney in what he told us, and his visit with bill clinton and president obama who stepped before the united nations general assembly talked about the recent violence against americans and explained a few things about our country to a global audience while putting some in the audience today on notice. we begin with our chief white house correspondent chuck todd. >> reporter: president obama and mitt romney jams as many meeting as they could today. they draw a contrast on serious issues and even less serious issues. the centerpiece of the president's visit to new york, his speech to the u.n. general assembly, focusing on the unrest in libya and the middle east. at times emotional. >> the attacks on the civilians from benghazi were attacks on americans. there should be no doubt that we will be relentless in tracking down the killers and bringi ini them to justice. and on this we must agree. >> reporter: president obama also drew a line in the sand about iraq's nuclear weapons. >> america wants to resolve this issue through true diplomacy and we need the time and space to do so. a nuclea